It’s one of the only changes in the special editions that I like, I think it can just be a simple edit to the audio track. I tried doing it myself but I couldn’t isolate the voices in the celebration scene so I could only let the music play but with no voices on top which feels weird to watch. I think someone could do it with a 5.1 mix, those usually have their own track for characters talking.
You might as well just use the audio from the Special Edition scene itself (rather than just the music from the soundtrack).
Well, I tried doing that but the timing of the shots is slightly different in the special edition